1. Field of the Invention
The present invention relates generally to the field of structures for supporting conductor wires, such as those connecting computer networks and voice systems, extending through the space above drop ceilings in warehouses and in virtually any other horizontal region within a building. More specifically the present invention relates to a conductor wire support system including a wire rope anchored at its ends to opposing structural points within a building and to a series of spaced apart hangers suspended from the wire rope, each hanger having engaging means for connecting to and supporting a conductor wire, or other system element.
Each hanger has a wire rope engaging end which slidingly wraps over the wire rope so that the hanger is radically pivotable entirely around the wire rope. This freedom to pivot assures that the hanger is always substantially perpendicular to the wire rope it engages, for balanced loading and even stress distribution. A wire rope gripping element is fitted within a notch in the engaging end of the hanger and is affixed to the wire rope, such as by crimping, to secure the hanger against substantial longitudinal movement along the wire rope while permitting the full pivoting movement about the wire rope.
2. Description of the Prior Art
There has been a continuing need for a support system for conductor wires which connect computer, voice and other communication systems within buildings. A problem has been that regulations such as fire codes do not permit the use of existing building structures to support such wires. Specialized independent hanger structures have generally served this need so far, but have notable disadvantages. One disadvantage has been that these devices require a building structure directly above for securing the device. The result has been that there are sometimes inappropriate gaps in the series of wire supporting devices in the regions where there is no suitable building structure immediately overhead.
There have long been various types of wire and cable support devices designed for other uses. Yet these devices are not well suited to meet typical conductor wire support needs. In some instances their use would be prohibited by applicable codes or regulations, such as a requirement that no weight and no clamping pressure be placed on conductor wires.
One such prior device is that of Bruno, U.S. Pat. No. 5,542,631, issued on Aug. 6, 1996. Bruno discloses an adjustable pipe hanger for suspending a pipe from a support structure at a desired angle relative to the support structure. The support structure may be a plank. The pipe hanger includes an elongate stem for mounting to the support structure, a rib integral with and extending along part of one side of the stem, and a hook that slides over the stem and rib and which may be rotated about one end of the stem and locked at any of several angles with respect to the support structure. A problem in using the Bruno pipe hanger for conductor wire support is that there must be a suitable building structure directly overhead each desired wire support point for fastening the pipe hanger. Another problem is that the pipe hanger appears to be narrow at its engaging end, so that loading on the conductor wire would be concentrated, increasing the likelihood of conductor wire deformation and damage.
Behrendt, et al., U.S. Pat. No. 5,314,155, issued on May 24, 1994, reveals a device for suspending a cable sleeve on a support cable. Behrendt, et al., includes a strip-shaped securing part which has one end fashioned as a hook and the other end fashioned as a mounting lug for securing to ends of the cable sleeve. The securing part is preferably provided with an arrangement to prevent accidental disengagement of the hook from the support cable. A problem with Behrendt, et al., is that it is directed to use where a cable sleeve is employed. It does not spread loading along the cable or conductor wire apart from use of the sleeve, and would likely damage a conductor wire if used for support without the sleeve. Each sleeve, on the other hand, requires two securing parts, so that costs are doubled.
McSherry, et al., U.S. Pat. No. 4,562,982, issued on Jan. 7, 1986, teaches a stackable cable spacer for preventing abrasion damage between support and signal transmission cables. McSherry, et al., interconnects a support cable with a signal transmission cable with a strap wrapped around both cables. A selected number of spacer elements separate the two cables, and the strap extends through passageways in the stacked spacer elements. The problems of Bruno are again presented.
Sachs, U.S. Pat. No. 4,526,428, issued on Jul. 2, 1985, for a multi-strand cable clamp with positive strand engagement, and Sachs, U.S. Pat. No. 4,014,504, issued on Mar. 29, 1977, for a cable hooking device, both disclose guy wire clamps with messenger wire holder engaging elements. The clamp includes opposing plates with angled intermeshing teeth to grip the guy wire, and a nut and bolt passing through the opposing plates to draw the plates together. If either Sachs device were used for supporting a conductor cable within a building, with the holder engaging elements retaining the conductor wire, the problems Behrendt, et al. would again be presented.
Van Dusen, Jr., U.S. Pat. No. 3,033,978, issued on May 8, 1962, teaches a catenary lighting apparatus. Van Dusen, Jr. includes light support units having spacers which are connected respectively to the upper and lower cables to tie them together at each lighting location. The spacers each include an offset portion adjacent the cable which is adapted to carry a service car to permit ready passage of the service car. The light unit is secured in place by a supporting member which is pivotally connected to the spacing means in spaced relation to the light supporting cable. The pivotally connected supporting member is normally arranged to maintain the center of gravity of the light support unit in the vertical plane of the cable and thus in the path of the service car. The pivotal suspension member may, however, be deflected or swung out of the way by the service man to provide ready passage of the cable car. A problem with Van Dusen, Jr. is that it does not broadly spread loading on the supported wire. Another problem is that it is complex and costly, having been designed for a very different purpose.
Mennerdahl, U.S. Pat. No. 3,289,983, issued on Dec. 6, 1966, reveals a device for carrying an electric cable. Mennerdahl includes a split ring portion for receiving the support cable and a leather strap extending downwardly from the ring portion and wrapping around the electric cable. The need to fit the support cable through the ring gap and then wrap the strap over the gap makes Mennerdahl relatively labor intensive to install.
Adams, U.S. Pat. No. 5,141,192, issued on Aug. 25, 1992, discloses an apparatus for hanging cords from a rain gutter or similar structure. Adams is essentially an extruded molded plastic or aluminum strip having loop contours to engage the rain gutter at one end and a wire such as for holiday light strings at the other end. Adams is not well suited to engage structures above drop ceilings to support a conductor wire, and otherwise presents the problems identified above for Bruno.
It is thus an object of the present invention to provide a support system within buildings for conductor wires connecting computers and other communication systems, which does not require an overhead building engaging structure for each conductor wire support.
It is another object of the present invention to provide such a support system which reduces the extensive labor associated with installing the numerous independently connected elements making up conventional support systems.
It is still another object of the present invention to provide such a support system which longitudinally spreads the surface area over which the support system elements engage the conductor wires to spread the loading on the conductor wire and thereby prevent sharp bends in the conductor wires, and maintain their transmission capabilities, meeting new high bandwidth requirements specified by the EIA/TIA Category 5 transmission standard.
It is finally an object of the present invention to provide such a support system which eliminates the need for workers to crawl through conductor wire routes to place individual support devices, with related drilling dust and clean-up, and which also eliminates the unsuitable practice of simply laying the conductor wires on top of ceiling structures.